Well I wanted to get into the 6 digits before taking a break, barely cracked the 100,000 barrier:
It's funny, I kept hitting reset on the runs where I died and lost the spread upgrade. With the spread upgrade I kept getting to the snail part of level one, and then would die. Then finally I had a horrible starting run and got to the phase two part with only 2 men and NO power ups. Then by some freak of luck I actually have the best run of the past hour or so and finished with the high score. Made it to the "boss" part and the mermaid killed me before I could even attack.
How dumb is that... I had made it to phase two fully upgraded with 4 or 5 men previously, but when I make it there with no upgrades and 2 men I do the best? Go figure...
Either way someone should be able to score in the 7 digits easily if they can beat the game, I'm having enough problems with level one right now though.